BALTIMORE — A study conducted by the Johns Hopkins Bloomberg School of Public Health’s Center for Human Nutrition estimated that if the number of overweight and obese individuals in the U.S. continues to climb at its current rate, 75% of adults and nearly 24% of U.S. children and adolescents will be overweight or obese by 2015. The study was published on-line on May 17 in advance of the 2007 issue of the journal Epidemiologic Reviews.
The prevalence of obese people in the United States increased from 13% to 32% between the 1960s and 2004, according to the study. Some minority and low socioeconomic status group, such as non-Hispanic black women and children, Mexican-American women and children, low socioeconomic status black men and white women and children, Native Americans and Pacific Islanders, are disproportionately affected.
"The obesity rate in the United States has increased at an alarming rate over the past three decades," said Dr. Youfa Wang, lead author of the study and assistant professor in the Bloomberg School of Public Health’s Department of International Health. "We set out to estimate the average annual increase in prevalence as well as the variation between population groups to predict the future situation regarding obesity and overweight individuals among U.S. adults and children. Obesity is a public health crisis. If the rate of obesity and overweight continues at this pace, by 2015, 75% of adults and nearly 24% of U.S. children and adolescents will be overweight or obese."
The study included 20 journal papers, reports and on-line data sets. In addition, data from four national surveys — the National Health and Nutrition Examination Survey, the Center for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System, Youth Risk Behavior Surveillance System and National Longitudinal Survey of Adolescent Health — were included in order to examine the disparities in obesity.
Adults were defined as overweight and obese based on body mass index (B.M.I.) cutoffs of 25 and 30, respectively. Children at risk for being overweight and obese were classified as being in the 85th and 95th percentiles of the B.M.I., respectively.
"Our analysis showed patterns of obesity or (being) overweight for various groups of Americans," said May A. Beydoun, co-author of the study and a postdoctoral fellow in the Bloomberg School of Public Health’s Department of International Health. "Obesity is likely to continue to increase, and if nothing is done, it will soon become the leading preventable cause of death in the United States."
Other key findings from the study include:
• Sixty-six per cent of U.S. adults were overweight or obese in 2003-2004.
• Eighty per cent of black women aged 40 years or over are overweight; 50% are obese.
• Asians have a lower obesity prevalence when compared to other ethnic groups. However, Asians born in the U.S. are four times more likely to be obese than their foreign-born counterparts.
• Less educated people have a higher prevalence of obesity than their counterparts, with the exception of black women.
• States in the southeast have a higher prevalence than states on the West Coast, the Midwest and the Northeast.
• Sixteen per cent of children and adolescents were overweight and 34% were at risk of becoming overweight in 2003-2004.
• White children and adolescents had the lowest prevalence of overweight and being at risk of overweight compared with their black and Mexican counterparts.